1. Field of the invention
The present invention relates to the detection of dental artefacts and, more particularly, to the detection of dental decay.
2. Description of the Prior Art
The removal of tartar, for instance with a scraper or a sonic or ultrasonic instrument, is important to prevent or to treat periodontal diseases, i.e. of tissues which surround the teeth, such as bone B, gums G, ligaments, etc. The tartar is calcified dental plaque that has accumulated on the tooth surface. Supergingival tartar and subgingival tartar S (see FIG. 2) must be removed as tartar is a porous substance which contains bacteria and which favours the accumulation of these pathogenic bacteria on its structure. Moreover, tartar mechanically irritates the gums.
In a healthy periodontium (see FIG. 1) there is no periodontal pocket. However, when there is a periodontal disease (FIG. 2), such a periodontal pocket P is formed by an inner surface of the gums G and by the root R of the tooth T and which is closed apically by the periodontal ligaments L. Subgingival tartar S can thus be found in this periodontal pocket P.
Therefore, to prevent periodontal problems which can lead to severe health problems, it is important to remove tartar from the tooth surface as it is forming; on the other hand, the removal of tartar is done with difficulty and in a groping manner, subgingival tartar being normally invisible to the human eye in normal conditions as it is covered by the gums. To remove subgingival tartar (i.e. located behind the gum), the operator must try to locate tartar by tactile feeling using a probe, but one cannot actually view subgingival tartar to ensure a complete removal thereof without resorting to invasive surgical procedures.
The use of an endoscopic method and device for the removal of subgingival tartar is also known from U.S. Pat. Nos. 5,230,621 and 5,328,365. In this system, an endoscopic probe is inserted in the gingival pocket or sulcus to endoscopically visualise the process of and/or effects of subgingival root planing, scaling or other plaque removal procedures carried out by other operative instruments. Alternatively, the endoscopic viewing apparatus may be incorporated in an operative instrument which itself is used to remove deposited material from subgingival tooth surfaces, whereby the operator may view and/or guide the instrument while using the plaque removal instrument itself. Therefore, the operator looks at a monitor that provides images of the endoscopic viewing and the operator detects the presence of subgingival tartar by looking at the monitor. This system is efficient, but somewhat cumbersome to use as the operator must stop looking into the mouth of the patient in order to look at the monitor. Moreover, this system is relatively expensive, as it requires a monitor and associated hardware.
Therefore, there is a need for a dental instrument which, using a probe or the like, can automatically detect the presence of subgingival tartar, which does not require the use of a monitor, and which allows the operator to concentrate on his/her task in the patient's mouth by not having to look at a monitor and thus leave the patients mouth from his/her sight. Such an instrument would facilitate the operator's task of removing subgingival tartar by providing a system which assists the operator in the diagnostic.